NE releases N-terminus CRT in patients with AML. (A) Recombinant full-length CRT protein was digested by NE at pH 6.0 and pH 7.4 for 2 hours. Coomassie staining depicted a band at 27 kDa. A Western blot analysis using an N-terminus CRT antibody is depicted below. (B) ELISA to detect human NE in 113 patients with AML at diagnosis and 7 healthy volunteers was performed. (C) The N-terminus CRT levels were correlated to NE levels (Pearson correlation coefficient: r = .2173; P < .05). (D) A total of 63 patients with AML could be investigated for the presence of the XBP1-spliced variant (positive: activated UPR; 19 patients vs negative: 44 patients). Patients with activated UPR had greater levels of N-terminal CRT (P < .001) but did not differ in serum neutrophil elastase levels (P = n.s.).